In the UK, many anti-war protesters took to the streets on bikes to express their opposition to the coalition assault. The protest caused traffic problems in cities including London and Sheffield and followed the wave of demonstrations across the UK yesterday.

Preparations continued for tomorrow's anti-war protest in central London, which is expected to attract tens of thousands of people from across the country.

Activists blockaded key US military headquarters in Germany. Anti-war protesters staged a sit-down blockade at the US military's European command in Stuttgart, snarling traffic on an access road until police peacefully removed the demonstrators.

In Berlin, schoolchildren placed candles on a street leading to the US embassy, which was sealed off by police, heavy concrete barriers and fences. Banners hung on police barriers carried slogans such as "common sense ends when violence begins" and "boycott US products".

Thousands of demonstrators gathered in Athens and in cities around Greece as a nationwide general strike to protest against the war in Iraq brought the country to a standstill.

Police said they were bracing themselves for an Athens demonstration expected to surpass a rally on Thursday that drew more than 100,000 people.

In Egypt, riot police used water cannons and attack dogs to keep anti-war demonstrators away from the US embassy.

Protesters hurled stones, pounded cars and shouted about the US and Egypt's leaders. "We want the flag down. We don't want America here at all," said one demonstrator.

In Buenos Aires, Argentina, federal police fired tear gas grenades and rubber bullets to scatter demonstrators who stoned the US embassy, burned an American flag and chanted slogans describing the US president, George Bush, as "a fascist terrorist".

Hundreds of Ecuadorans marched on the US embassy in the capital, Quito, burning US flags and chanting "Bush is an assassin".

At least 11,000 people marched through Tokyo after Mr Bush thanked the prime minister of pacifist Japan for joining the "coalition of the willing" against Saddam Hussein.

Opinion polls show that the conflict is extremely unpopular in a country with bitter memories of its crushing defeat in the second world war and which has a pacifist constitution prohibiting the deployment of combat troops abroad.

More than 5,000 people rallied in the streets of Melbourne after the Australian military confirmed its special forces were in Iraq with British and US forces identifying targets for coalition aircraft and monitoring enemy troop movements.

In Indonesia, the world's most populous Muslim nation, protesters threw eggs and vegetables at the British embassy in the capital, Jakarta.

Demonstrators in the second largest city, Surabaya, rallied outside the US consulate. Elsewhere, groups besieged American fast food restaurants and banks.

President Megawati Sukarnoputri has condemned the war as a violation of international law. Indonesian Muslim leaders have called Mr Bush a terrorist.

Dozens of activists converged on the American embassy in Buddhist Thailand. About 7,000 Muslims in Kota Baharu city in eastern Malaysia burned British and US flags as well as effigies of Mr Bush and British prime minister, Tony Blair.

Thousands of people took to the streets of the Bangladesh capital, Dhaka, after Muslim prayers to protest the attack on Iraq. Riot police watched as Muslim devotees - wearing traditional long robes and prayer caps - rallied outside the central mosque in downtown Dhaka, despite a drizzling rain.

In Pakistan, the nation's religious right called for peaceful protests against the war but withdrew demands for a nationwide strike, saying it would hurt ordinary Pakistanis.

Today's demonstrations came a day after thousands of activists around the United States launched a barrage of anti-war protests, chaining themselves together, blocking traffic, walking out of classes and parading in mock chemical suits.

But the anti-war groundswell also brought out thousands of counter-demonstrators. One in Mississippi carried a sign saying "support the US or keep your mouth shut."